A direct methanol fuel cell is provided with an anode to which an aqueous methanol solution is supplied as the fuel, a cathode to which oxidizing gas is supplied, an electrolyte membrane interposed between these electrodes, a fuel separator which is disposed in the anode and has a fuel passage and a cathode separator which is disposed in the cathode and has an oxidizing gas passage. The separator is conventionally used a carbon plate or SUS plate and formed with a passage several millimeters deep by cutting or pressing.
However, it is difficult to decrease the thickness of each separator because a passage several millimeters deep is formed on the separator. As a result, a fuel cell provided with this separator is increased in whole thickness, causing an increase in weight, resulting in low output density.